Oacoma, South Dakota

• Open map evidence
• Research guide
• Lyman County

Oacoma fell from 451 to 386 between 2010 and 2020. These are the recorded population figures Wikidata holds for this place, reached through the Geographic Names Information System number this page is keyed on rather than by name, so they belong to this place and not to another of the same name. Most are census counts, but not all are: an early figure may be a founding or settlement estimate, and an estimate published within five years of a census is left out. The change column is computed, and is left blank where more than 20 years separate a figure from the one before it, because a gap that long is not a change between two counts.

Matched by testing this settlement's coordinate against the published boundary of every sheet in the United States Geological Survey's historical collection. Each opens the scanned sheet at the Survey.

• 1935 USGS Chamberlain quadrangle1:62500
• 1939 USGS Chamberlain quadrangle1:62500, 2 printings
• 1952 USGS Oacoma quadrangle1:24000
• 1955 USGS Mitchell quadrangle1:250000, 2 printings
• 1959 USGS Mitchell quadrangle1:250000, 2 printings
• 1986 USGS Chamberlain quadrangle1:100000, 2 printings
• 1990 USGS Mitchell quadrangle1:250000

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 36 fires within 5 miles of Oacoma between 2010 and 2020, burning about 862 acres in total. None started naturally. None was recorded as arson. Distance is straight-line from the map coordinates, so a fire counted here may appear on a neighbouring settlement's page as well.

The most recent of them, most recent first, with the day each was reported and the service that recorded it.

Every fire recorded in Lyman County

Regional context, not property-specific evidence. The federal mineral resources record lists 5 workings within 5 miles of Oacoma: 4 past producers, 1 unknown. None of them still produces. What was taken out: Sand and Gravel, Construction, Manganese. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.

Every working recorded in Lyman County

Regional context, not property-specific evidence. The National Weather Service names Oacoma in 66 storm reports between 1996 and 2025: 44 thunderstorm wind, 18 hail, 2 flash flood, 1 flood. No death or injury is recorded in these reports. Each account below is quoted exactly as the forecast office filed it, from the NOAA Storm Events Database, and each date opens the federal record of that event.

Every storm recorded in Lyman County

The eight closest, with where each one stands in the county. Distances are straight-line, computed from the Geographic Names Information System coordinates.

Matched on this settlement's Geographic Names Information System number rather than its name, so it cannot be a different place of the same name in another state.

This settlement is recorded in the Geographic Names Information System as feature 1265308. The sheet list is computed by point-in-boundary test against the United States Geological Survey's historical topographic inventory. Both are works of the United States government and carry no copyright under 17 U.S.C. 105.

Wildfire. Short, Karen C. 2022. Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014]. 6th Edition. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.6 Collected with United States Government funding and usable without additional permissions or fees.

Mines and quarries. USGS Mineral Resources Data System (MRDS) https://mrdata.usgs.gov/mrds/ A work of the United States government, no copyright under 17 U.S.C. 105.

Storms. NOAA National Centers for Environmental Information, Storm Events Database https://www.ncei.noaa.gov/stormevents/ A work of the United States government, no copyright under 17 U.S.C. 105. Narratives are quoted verbatim from the National Weather Service report and are not edited or summarised.